History of the Peloponnesian War

When finally the armies were at close quarters and the Peloponnesians outflanked with their left the right wing of their opponents and were about to encircle it, the Acarnanians, coming upon them from their ambush, fell upon their rear and routed them, so that they did not stand to make resistance and in their panic caused the greater part of their army to take to flight also; for when they saw the division under Eurylochus, their best troops, being cut to pieces, they were far more panic-stricken. And it was the Messenians, who were in this part of the field under the command of Demosthenes, that bore the brunt of the battle.

On the other hand, the Ambraciots and those on the enemy's right wing defeated the troops opposed to themselves, and pursued them to Argos; and indeed these are the best fighters of all the peoples of that region.

When, however, they returned and saw that their main army had been defeated, and the victorious division of the Acarnanians began to press hard upon them, they made their escape with difficulty to Olpae; and many of them were killed, for they rushed on with broken ranks and in disorder all except the Mantineans, who kept their ranks together during the retreat better than any other part of the army. And it was late in the evening before the battle ended.